2008 Joint Annual Meeting (5-9 Oct. 2008): Confirmation of Differential Expression of Selected Genes Expressed Under High Temperature Stress in Wheat by Real-Time PCR.

734-8 Confirmation of Differential Expression of Selected Genes Expressed Under High Temperature Stress in Wheat by Real-Time PCR.



Wednesday, 8 October 2008
George R. Brown Convention Center, Exhibit Hall E
Md. Babar1, Allan Fritz2, John Fellers3, J. Bai4 and M. Deshpande4, (1)Kansas State University - Entomology, Kansas State University, 2004 Throckmorton Plant Science Ctr, Manhattan, KS 66506
(2)Kansas State University - Plant Pathology, Dept. of Agronomy, Throckmorton Hall KSU, Manhattan, KS 66506-5501
(3)USDA-ARS, USDA-ARS Kansas State University, 4006 Throckmorton Hall, Manhattan, KS 66506
(4)Plant Pathology, Kansas State University, Manhattan, KS 66506
Real-time PCR allows quantification of starting amount of messenger RNA in real-time.  Real-time PCR can compare mRNA levels of a gene of interest between different experimental conditions, and thus can confirm expression level of that gene. A microarray gene expression study was carried out in wheat under high temperature stress conditions to find genes related to long-term heat stress tolerance in wheat. The objectives of the present study were confirmation of the expression of selected genes potentially related to heat tolerance. A subset of 14 ESTs was selected from microarray experiments based on the significant expression level of those genes under heat-stress conditions in two sampling dates. Leaf tissues were collected at 4, 7, and 10 days from both heat-treated and control plants. A total of 48 cDNA samples (24 from offspring and 24 from parents) were used in the study. House keeping gene   β-actin was used to adjust the concentration of cDNA, and a dilution series was used to estimate primer efficiency. Six different genes, namely Rubisco activase, IP3 kinase B, a Zinc finger protein, a Leucine Rich Repeat protein, a RNA binding protein, an auxin efflux carrier protein, showed consistently higher expression in tolerant lines. On the other hand, thaumatin-like protein, Abscisic acid-inducible protein kinase, Pheophorbide a oxygenase, Clp protease, and Papain family cysteine protease were consistently higher expressed in sensitive lines. Results from Real-Time PCR confirmed their differential expression. The differential expression of those genes may be attributed to genotypic variations in response to heat stress. The up-regulated genes in the tolerant lines might have potential to be related to the heat tolerance, while the genes up-regulated in sensitive lines could be potentially related to rate limiting factor of senescence under heat stress conditions.